The ms. Namur, Archives de l’État, Arch. Eccl. 1664, contains the income and expense account of the chapter of the canonesses of noble birth in Moustier-sur-Sambre for the period of August 5, 1563, to August 4, 1564. In the xvith century, a section of this register was protected with three leaves of parchment (one bifolio leaf and one plain leaf) from a manuscript datable to the xiiith century. The bifolio leaf, of which only the central portion remains, contains excerpts from the Roman de Merlin (ed. A. Micha, ch. 76, l. 49–59; ch. 77, l. 1–26; ch. 78, l. 63–70; ch. 79, l. 1–55; ch. 80, l. 58–64; ch. 81, l. 1–26), while the simple leaf, which is better preserved, contains an excerpt from the Suite Vulgate (ed. I. Freire-Nunes, from § 210, l. 11, to § 213, l. 25). The purpose of this paper is to publish this original fragment, describing it in detail, and to provide a linguistic and philological analysis. This discovery opens interesting perspectives on the distribution of Arthurian literature in Wallonia.